Coating compositions containing alkoxy substituted perfluoro compounds

ABSTRACT

A process for removing contaminants from the surface of a substrate comprises contacting the substrate with a cleaning composition comprising at least one mono-, di-, or trialkoxy-substituted perfluoroalkane, perfluorocycloalkane, perfluorocycloalkyl-containing perfluoroalkane, or perfluorocycloalkylene-containing perfluoroalkane compound, the compound optionally containing additional catenary heteroatoms. The compounds exhibit good solvency properties while being environmentally acceptable.

This application is a continuation of application Ser. No. 09/867,169filed, May 29, 2001, now U.S. Pat. No. 6,380,149 which is a divisionalof Ser. No. 09/268,236 U.S. Pat. No. 6,291,417, issued Sep. 18, 2001,which is a continuation-in-part of Ser. No. 08/573,416 U.S. Pat. No.5,925,611, issued Jul. 20, 1999, which was a continuation-in-part ofapplication Ser. No. 08/375,812 filed Jan. 20, 1995, now abandoned.

FIELD OF THE INVENTION

This invention relates to cleaning compositions comprising at least onepartially-fluorinated ether compound and to processes for removingcontaminants from substrate surfaces using such compositions. In anotheraspect, this invention relates to certain novel partially-fluorinatedether compounds. In yet another aspect, this invention relates tocoating compositions comprising at least one partially-fluorinated ethercompound and to processes for depositing coatings on substrate surfacesusing such compositions.

BACKGROUND OF THE INVENTION

Solvent cleaning applications where contaminated articles are immersedin (or washed with) solvent liquids and/or vapors are well-known.Applications involving one or more stages of immersion, rinsing, and/ordrying are common. Solvents can be used at ambient temperature (often,accompanied by ultrasonic agitation) or at elevated temperatures up tothe boiling point of the solvent.

A major concern in solvent cleaning is the tendency (especially wheresolvent is used at an elevated temperature) for solvent vapor loss fromthe cleaning system into the atmosphere. Although care is generallyexercised to minimize such losses (e.g., through good equipment designand vapor recovery systems), most practical cleaning applications resultin some loss of solvent vapor into the atmosphere.

Solvent cleaning processes have traditionally utilized chlorinatedsolvents (e.g., chlorofluorocarbons such as1,1,2-trichloro-1,2,2-trifluoroethane and chlorocarbons such as1,1,1-trichloroethane) alone or in admixture with one or more cosolventssuch as aliphatic alcohols or other low molecular weight, polarcompounds. Such solvents were initially believed to beenvironmentally-benign, but have now been linked to ozone depletion.According to the Montreal Protocol and its attendant amendments,production and use of the solvents must be discontinued (see, e.g., P.S. Zurer, “Looming Ban on Production of CFCs, Halons Spurs Switch toSubstitutes,” Chemical & Engineering News, page 12, Nov. 15, 1993).

Thus, there has developed a need in the art for substitutes orreplacements for the commonly-used cleaning solvents. Such substitutesshould have a low ozone depletion potential, should have boiling rangessuitable for a variety of solvent cleaning applications, and should havethe ability to dissolve both hydrocarbon-based and fluorocarbon-basedsoils. Preferably, substitutes will also be low in toxicity, have noflash points (as measured by ASTM D3278-89), have acceptable stabilityfor use in cleaning applications, and have short atmospheric lifetimesand low global warming potentials.

Partially-fluorinated ethers have been suggested as chlorofluorocarbonalternatives (see, e.g., Yamashita et al., International Conference onCFC and BFC (Halons), Shanghai, China, Aug. 7-10, 1994, pages 55-58).

European Patent Publication No. 0 450 855 A2 (Imperial ChemicalIndustries PLC) describes the use of low molecular weight,fluorine-containing ethers of boiling point 20-120° C. in solventcleaning applications.

International Patent Publication No. WO 93/11280 (Allied-Signal, Inc.)discloses a non-aqueous cleaning process which utilizes afluorocarbon-based rinsing solvent.

U.S. Pat. No. 5,275,669 (Van Der Puy et al.) describes hydrofluorocarbonsolvents useful for dissolving contaminants or removing contaminantsfrom the surface of a substrate. The solvents have 4 to 7 carbon atomsand have a portion which is fluorocarbon, the remaining portion beinghydrocarbon.

U.S. Pat. No. 3,453,333 (Litt et al.) discloses fluorinated etherscontaining at least one halogen substituent other than fluorine andstates that those ethers which are liquid can be used as solvents forhigh molecular weight resinous perhalogenated compounds such as solidpolychlorotrifluoroethylene resins.

French Patent Publication No. 2,287,432 (Societe Nationale des Poudreset Explosifs) describes new partially-fluorinated ethers and a processfor their preparation. The compounds are said to be useful as hypnoticand anesthetic agents; as monomers for preparing heat-stable,fire-resistant, or self-lubricant polymers; and in phyto-sanitary andphyto-pharmaceutical fields.

German Patent Publication No. 1,294,949 (Farbwerke Hoechst AG) describesa technique for the production of perfluoroalkyl-alkyl ethers, said tobe useful as narcotics and as intermediates for the preparation ofnarcotics and polymers.

SUMMARY OF THE INVENTION

In one aspect, this invention provides a process for removingcontaminants (e.g., hydrocarbons, fluorocarbons, or even water) from thesurface of a substrate (e.g., metal, glass, ceramic, plastic, orfabric). The process comprises contacting the substrate with (orexposing the substrate to) a liquid- and/or vapor-phase cleaningcomposition comprising at least one mono-, di-, or trialkoxy-substitutedperfluoroalkane, perfluorocycloalkane, perfluorocycloalkyl-containingperfluoroalkane, or perfluorocycloalkylene-containing perfluoroalkanecompound. The compound can optionally contain additional catenary (i.e.,in-chain) heteroatoms (e.g., oxygen or nitrogen) and preferably has aboiling point in the range of from about 25° C. to about 200° C.

The alkoxy-substituted compounds used in the process of the inventionexhibit unexpectedly high stabilities in the presence of acids, bases,and oxidizing agents. In addition, in spite of their fluorine content,the compounds are surprisingly good solvents for hydrocarbons (as wellas fluorocarbons). The compounds are low in toxicity and flammability,have ozone depletion potentials of zero, and have short atmosphericlifetimes and low global warming potentials relative tochlorofluorocarbons and many chlorofluorocarbon substitutes. Since thecompounds exhibit good solvency properties while being environmentallyacceptable, they satisfy the need in the art for substitutes orreplacements for the commonly-used cleaning solvents which have beenlinked to the destruction of the earth's ozone layer.

In other aspects, this invention also provides certain novel mono-, di-,and trialkoxy-substituted perfluorocompounds; a cleaning composition; acoating composition; and a process for depositing coatings (e.g.,coatings of lubricant) on substrate surfaces.

DETAILED DESCRIPTION OF THE INVENTION

Compounds which can be utilized in the processes of the invention aremono-, di-, or trialkoxy-substituted perfluoroalkane,perfluorocycloalkane, perfluorocycloalkyl-containing perfluoroalkane,and perfluorocycloalkylene-containing perfluoroalkane compounds. Thecompounds include those which contain additional catenary heteroatoms(as well as those which do not) and can be utilized alone, incombination with one another, or in combination with other commoncleaning solvents (e.g., alcohols, ethers, alkanes, alkenes,perfluorocarbons, perfluorinated tertiary amines, perfluoroethers,cycloalkanes, esters, ketones, aromatics, siloxanes, hydrochlorocarbons,hydrochlorofluorocarbons, and hydrofluorocarbons). The compounds can besolids or liquids under ambient conditions of temperature and pressure,but are generally utilized for cleaning in either the liquid or thevapor state (or both). Thus, normally solid compounds can be utilizedafter tranformation to liquid and/or vapor through melting, sublimation,or dissolution in liquid co-solvent.

A class of useful alkoxy-substituted perfluorocompounds is that whichcan be represented by the following general formula (I):

R_(f)—(O—R_(h))_(x)  (I)

wherein x is an integer of 1 to 3; when x is 1, R_(f) is selected fromthe group consisting of linear or branched perfluoroalkyl groups havingfrom 2 to about 15 carbon atoms, perfluorocycloalkyl-containingperfluoroalkyl groups having from 5 to about 15 carbon atoms, andperfluorocycloalkyl groups having from 3 to about 12 carbon atoms; whenx is 2, R_(f) is selected from the group consisting of linear orbranched perfluoroalkanediyl groups or perfluoroalkylidene groups havingfrom 2 to about 15 carbon atoms, perfluorocycloalkyl- orperfluorocycloalkylene-containing perfluoroalkanediyl orperfluoroalkylidene groups having from 6 to about 15 carbon atoms, andperfluorocycloalkanediyl groups or perfluorocycloalkylidene groupshaving from 3 to about 12 carbon atoms; when x is 3, R_(f) is selectedfrom the group consisting of linear or branched perfluoroalkanetriylgroups having from 2 to about 15 carbon atoms, perfluorocycloalkyl- orperfluorocycloalkylene-containing perfluoroalkanetriyl groups havingfrom 6 to about 15 carbon atoms, and perfluorocycloalkanetriyl groupshaving from 3 to about 12 carbon atoms; each R_(h) is independentlyselected from the group consisting of linear or branched alkyl groupshaving from 1 to about 8 carbon atoms, cycloalkyl-containing alkylgroups having from 4 to about 8 carbon atoms, and cycloalkyl groupshaving from 3 to about 8 carbon atoms; wherein either or both of thegroups R_(f) and R_(h) can contain (optionally contain) one or morecatenary heteroatoms; and wherein the sum of the number of carbon atomsin R_(f) and the number of carbon atoms in R_(h) is greater than orequal to 4. The perfluorocycloalkyl and perfluorocycloalkylene groupscontained within the perfluoroalkyl, perfluoroalkanediyl,perfluoroalkylidene and perfluoroalkanetriyl groups can optionally (andindependently) be substituted with, e.g., one or more perfluoroalkylgroups having from 1 to about 4 carbon atoms.

Preferably, x is 1; R_(f) is as defined above; R_(h) is an alkyl grouphaving from 1 to about 6 carbon atoms; R_(f) but not R_(h) can containone or more catenary heteroatoms; and the sum of the number of carbonatoms in R_(f) and the number of carbon atoms in R_(h) is greater thanor equal to 4. Most preferably, x is 1; R_(f) is selected from the groupconsisting of linear or branched perfluoroalkyl groups having from 3 toabout 6 carbon atoms, perfluorocycloalkyl-containing perfluoroalkyl orperfluoroalkylidene groups having from 5 to about 8 carbon atoms, andperfluorocycloalkyl groups having from 5 to about 6 carbon atoms; R_(h)is an alkyl group having from 1 to about 3 carbon atoms; R_(f) but notR_(h) can contain one or more catenary heteroatoms; and the sum of thenumber of carbon atoms in R_(f) and the number of carbon atoms in R_(h)is greater than or equal to 4. The perfluorocycloalkyl andperfluorocycloalkylene groups contained within the perfluoroalkyl,perfluoroalkanediyl, perfluoroalkylidene and perfluoroalkanetriyl groupscan optionally (and independently) be substituted with, e.g., one ormore perfluoromethyl groups. These compounds are preferred due to theirease of preparation and their performance characteristics.

Representative examples of alkoxy-substituted perfluorocompoundssuitable for use in the processes of the invention include the followingcompounds:

C₃F₇CF(OC₂H₅)CF(CF₃)₂, C₂F₅CF(OC₂H₅)CF(CF₃)₂, C₂F₅CF(OCH₃)CF(CF₃)₂,CF₃CF(OCH₃)CF(CF₃)₂, 1,1-dimethoxyperfluorocyclohexane, and mixturesthereof, where cyclic structures having an interior “F” areperfluorinated.

A novel subclass of the alkoxy-substituted perfluorocompounds is thatwhich can be represented by the following general formula (II):

R_(f) ¹—N(R_(f) ²)13 C_(y)F_(2y)—O—R_(h)  (II)

wherein R_(f) ¹ and R_(f) ² are both substituted or unsubstitutedperfluoroalkyl groups having from 1 to about 6 carbon atoms or are bothsubstituted or unsubstituted perfluoroalkylene groups having from 2 toabout 4 carbon atoms, the perfluoroalkylene groups being bonded to oneanother to form a ring; y is an integer of 1 to about 8; C_(y)F_(2y) canbe linear or branched; and R_(h) is selected from the group consistingof linear or branched alkyl groups having from 1 to about 8 carbonatoms, cycloalkyl-containing alkyl groups having from 4 to about 8carbon atoms, and cycloalkyl groups having from 3 to about 8 carbonatoms; wherein the groups R_(f) ¹, R_(f) ², and R_(h) can optionally(and independently) contain one or more catenary heteroatoms.

Preferably, the perfluoroalkyl groups have from 1 to about 3 carbonatoms, the perfluoroalkylene groups have from 2 to about 3 carbon atoms;y is an integer of 1 to about 3; R_(h) is selected from the groupconsisting of linear or branched alkyl groups having from 1 to about 6carbon atoms; and R_(f) ¹ and R_(f) ² but not R_(h) can independentlycontain one or more catenary heteroatoms. These compounds are preferreddue to their ease of preparation and their performance characteristics.

Representative examples of novel compounds according to Formula II aboveinclude the following compounds:

A second novel subclass of the alkoxy-substituted perfluorocompounds isthat which can be represented by the following general formula (III):

R_(f) ³(CF₂OR_(h))_(x′)  (III)

wherein R_(f) ³ is a substituted or unsubstituted perfluorocycloalkyl,perfluorocycloalkanediyl, or perfluorocycloalkanetriyl group having from3 to about 12 carbon atoms; each R_(h) is independently selected fromthe group consisting of linear or branched alkyl groups having from 1 toabout 8 carbon atoms, cycloalkyl-containing alkyl groups having from 4to about 8 carbon atoms, and cycloalkyl groups having from 3 to about 8carbon atoms; and x′ is an integer of 1 to 3; wherein either or both ofthe groups R_(f) ³ and R_(h) can contain (optionally contain) one ormore catenary heteroatoms.

Preferably, R_(f) ³ has from 5 to about 6 carbon atoms; each R_(h) isindependently selected from the group consisting of linear or branchedalkyl groups having from 1 to about 6 carbon atoms; x′ is an integer of1 or 2; and R_(f) ³ but not R_(h) can contain one or more catenaryheteroatoms. These compounds are preferred due to their ease ofpreparation and their performance characteristics.

Representative examples of novel compounds according to Formula IIIabove include the following compounds:

The alkoxy-substituted perfluorocompounds suitable for use in theprocess of the invention can be prepared by alkylation of perfluorinatedalkoxides prepared by the reaction of the corresponding perfluorinatedacyl fluoride or perfluorinated ketone with an anhydrous alkali metalfluoride (e.g., potassium fluoride or cesium fluoride) or anhydroussilver fluoride in an anhydrous polar, aprotic solvent. (See, e.g., thepreparative methods described in French Patent Publication No. 2,287,432and German Patent Publication No. 1,294,949, supra.) Alternatively, afluorinated tertiary alcohol can be allowed to react with a base, e.g.,potassium hydroxide or sodium hydride, to produce a perfluorinatedtertiary alkoxide which can then be alkylated by reaction withalkylating agent.

Suitable alkylating agents for use in the preparation include dialkylsulfates (e.g., dimethyl sulfate), alkyl halides (e.g., methyl iodide),alkyl p-toluenesulfonates (e.g., methyl p-toluenesulfonate), alkylperfluoroalkanesulfonates (e.g., methyl perfluoromethanesulfonate), andthe like. Suitable polar, aprotic solvents include acyclic ethers suchas diethyl ether, ethylene glycol dimethyl ether, and diethylene glycoldimethyl ether; carboxylic acid esters such as methyl formate, ethylformate, methyl acetate, diethyl carbonate, propylene carbonate, andethylene carbonate; alkyl nitriles such as acetonitrile; alkyl amidessuch as N,N-dimethylformamide, N,N-diethylformamide, andN-methylpyrrolidone; alkyl sulfoxides such as dimethyl sulfoxide; alkylsulfones such as dimethylsulfone, tetramethylene sulfone, and othersulfolanes; oxazolidones such as N-methyl-2-oxazolidone; and mixturesthereof.

Perfluorinated acyl fluorides (for use in preparing thealkoxy-substituted perfluorocompounds) can be prepared byelectrochemical fluorination (ECF) of the corresponding hydrocarboncarboxylic acid (or a derivative thereof), using either anhydroushydrogen fluoride (Simons ECF) or KF.2HF (Phillips ECF) as theelectrolyte. Perfluorinated acyl fluorides and perfluorinated ketonescan also be prepared by dissociation of perfluorinated carboxylic acidesters (which can be prepared from the corresponding hydrocarbon orpartially-fluorinated carboxylic acid esters by direct fluorination withfluorine gas). Dissociation can be achieved by contacting theperfluorinated ester with a source of fluoride ion under reactingconditions (see the method described in U.S. Pat. No. 3,900,372(Childs), the description of which is incorporated herein by reference)or by combining the ester with at least one initiating reagent selectedfrom the group consisting of gaseous, non-hydroxylic nucleophiles;liquid, non-hydroxylic nucleophiles; and mixtures of at least onenon-hydroxylic nucleophile (gaseous, liquid, or solid) and at least onesolvent which is inert to acylating agents.

Initiating reagents which can be employed in the dissociation are thosegaseous or liquid, non-hydroxylic nucleophiles and mixtures of gaseous,liquid, or solid, non-hydroxylic nucleophile(s) and solvent (hereinaftertermed “solvent mixtures”) which are capable of nucleophilic reactionwith perfluorinated esters. The presence of small amounts of hydroxylicnucleophiles can be tolerated. Suitable gaseous or liquid,non-hydroxylic nucleophiles include dialkylamines, trialkylamines,carboxamides, alkyl sulfoxides, amine oxides, oxazolidones, pyridines,and the like, and mixtures thereof. Suitable non-hydroxylic nucleophilesfor use in solvent mixtures include such gaseous or liquid,non-hydroxylic nucleophiles, as well as solid, non-hydroxylicnucleophiles, e.g., fluoride, cyanide, cyanate, iodide, chloride,bromide, acetate, mercaptide, alkoxide, thiocyanate, azide,trimethylsilyl difluoride, bisulfite, and bifluoride anions, which canbe utilized in the form of alkali metal, ammonium, alkyl-substitutedammonium (mono-, di-, tri-, or tetra-substituted), or quaternaryphosphonium salts, and mixtures thereof. Such salts are in generalcommercially available but, if desired, can be prepared by knownmethods, e.g., those described by M. C. Sneed and R. C. Brasted inComprehensive Inorganic Chemistry, Volume Six (The Alkali Metals), pages61-64, D. Van Nostrand Company, Inc., New York (1957), and by H. Kobleret al. in Justus Liebigs Ann. Chem. 1978, 1937.1,4-diazabicyclo[2.2.2]octane and the like are also suitable solidnucleophiles.

The cleaning process of the invention can be carried out by contacting acontaminated substrate with a cleaning composition comprising at leastone of the above-described alkoxy-substituted perfluorocompounds. Theperfluorocompounds can be utilized alone or in admixture with each otheror with other commonly-used cleaning solvents, e.g., alcohols, ethers,alkanes, alkenes, perfluorocarbons, perfluorinated tertiary amines,perfluoroethers, cycloalkanes, esters, ketones, aromatics, siloxanes,hydrochlorocarbons, hydrochlorofluorocarbons, hydrofluorocarbons, andmixtures thereof. Such co-solvents can be chosen to modify or enhancethe solvency properties of a cleaning composition for a particular useand can be utilized in ratios (of co-solvent to perfluorocompound(s))such that the resulting composition has no flash point. Preferably, theperfluorocompound(s) constitute at least about 30 weight percent of thecomposition (more preferably, greater than about 50 weight percent,i.e., a major amount; most preferably, at least about 60 weightpercent), based upon the sum of the weights of the perfluorocompound(s)and the co-solvent(s). The perfluorocompound(s) used in the compositionpreferably have boiling points in the range of from about 25° C. toabout 200° C., more preferably from about 25° C. to about 125° C. Ifdesirable for a particular application, the cleaning composition canfurther contain one or more dissolved or dispersed gaseous, liquid, orsolid additives (for example, carbon dioxide gas, surfactants,stabilizers, antioxidants, or activated carbon).

The cleaning composition can be used in either the gaseous or the liquidstate (or both), and any of the known techniques for “contacting” asubstrate can be utilized. For example, a liquid cleaning compositioncan be sprayed or brushed onto the substrate, a gaseous cleaningcomposition can be blown across the substrate, or the substrate can beimmersed in either a gaseous or a liquid composition. Elevatedtemperatures, ultrasonic energy, and/or agitation can be used tofacilitate the cleaning. Various different solvent cleaning techniquesare described by B. N. Ellis in Cleaning and Contamination ofElectronics Components and Assemblies, Electrochemical PublicationsLimited, Ayr, Scotland, pages 182-94 (1986).

Both organic and inorganic substrates can be cleaned by the process ofthe invention. Representative examples of the substrates include metals;ceramics; glass; polycarbonate; polystyrene;acrylonitrile-butadiene-styrene copolymer; natural fibers (and fabricsderived therefrom) such as cotton, silk, fur, suede, leather, linen, andwool; synthetic fibers (and fabrics) such as polyester, rayon, acrylics,nylon, and blends thereof; fabrics comprising a blend of natural andsynthetic fibers; and composites of the foregoing materials. The processis especially useful in the precision cleaning of electronic components(e.g., circuit boards), optical or magnetic media, and medical devices.

The cleaning process of the invention can be used to dissolve or removemost contaminants from the surface of a substrate. For example,materials such as light hydrocarbon contaminants; higher molecularweight hydrocarbon contaminants such as mineral oils and greases;fluorocarbon contaminants such as perfluoropolyethers,bromotrifluoroethylene oligomers (gyroscope fluids), andchlorotrifluoroethylene oligomers (hydraulic fluids, lubricants);silicone oils and greases; solder fluxes; particulates; and othercontaminants encountered in precision, electronic, metal, and medicaldevice cleaning can be removed. The process is particularly useful forthe removal of hydrocarbon contaminants (especially, light hydrocarbonoils), fluorocarbon contaminants, particulates, and water (as describedin the next paragraph).

To displace or remove water from substrate surfaces, the cleaningprocess of the invention can be carried out as described in U.S. Pat.No. 5,125,978 (Flynn et al.) by contacting the surface of an articlewith a liquid cleaning composition which preferably contains a non-ionicfluoroaliphatic surface active agent. (Although non-ionicfluoroaliphatic surface active agents or surfactants are preferred,other surfactants that are sufficiently soluble or dispersible in thealkoxy-substituted perfluorocompound-containing cleaning composition canbe utilized, if desired.) The wet article is immersed in the liquidcomposition and agitated therein, the displaced water is separated fromthe liquid composition, and the resulting water-free article is removedfrom the liquid composition. Further description of the process and thearticles which can be treated are found in said U.S. Pat. No. 5,125,978,which description is incorporated herein by reference. The process canalso be carried out as described in U.S. Pat. No. 3,903,012 (Brandreth),the description of which is also incorporated herein.

This invention also provides a cleaning composition comprising (a) amajor amount (greater than about 50 weight percent; preferably, at leastabout 60 weight percent) of at least one mono-, di-, ortrialkoxy-substituted perfluoroalkane, perfluorocycloalkane,perfluorocycloalkyl-containing perfluoroalkane, orperfluorocycloalkylene-containing perfluoroalkane compound, the compoundoptionally containing additional catenary heteroatoms; and (b) a minoramount (less than about 50 weight percent; preferably, less than about40 weight percent) of at least one co-solvent; said weight percentsbeing based upon the sum of the weights of the perfluorocompound(s)(component (a) of the cleaning composition) and the co-solvent(s)(component (b) of the cleaning composition). Preferably, the co-solventis selected from the group consisting of alcohols, ethers, alkanes,alkenes, haloalkenes, perfluorocarbons, perfluorinated tertiary amines,perfluoroethers, cycloalkanes, esters, ketones, aromatics,haloaromatics, siloxanes, hydrochlorocarbons, hydrochlorofluorocarbons,hydrofluorocarbons, and mixtures thereof(more preferably, alcohols,alkanes, alkenes, haloalkenes, cycloalkanes, esters, aromatics,haloaromatics, hydrochlorocarbons, hydrofluorocarbons, and mixturesthereof; most preferably, alcohols, alkanes, alkenes, haloalkenes,cycloalkanes, esters, aromatics, haloaromatics, and mixtures thereof).

Representative examples of co-solvents which can be used in the cleaningcomposition include methanol, ethanol, isopropanol, t-butyl alcohol,methyl t-butyl ether, methyl t-amyl ether, 1,2-dimethoxyethane,cyclohexane, 2,2,4-trimethylpentane, n-decane, terpenes (e.g., a-pinene,camphene, and limonene), trans-1,2-dichloroethylene,cis-1,2-dichloroethylene, methylcyclopentane, decalin, methyl decanoate,t-butyl acetate, ethyl acetate, diethyl phthalate, 2-butanone, methylisobutyl ketone, naphthalene, toluene, p-chlorobenzotrifluoride,trifluorotoluene, bis(trifluoromethyl)benzenes, hexamethyl disiloxane,octamethyl trisiloxane, perfluorohexane, perfluoroheptane,perfluorooctane, perfluorotributylamine, perfluoro-N-methyl morpholine,perfluoro-2-butyl oxacyclopentane, methylene chloride,chlorocyclohexane, 1-chlorobutane, 1,1-dichloro-1-fluoroethane,1,1,1-trifluoro-2,2-dichloroethane,1,1,1,2,2-pentafluoro-3,3-dichloropropane,1,1,2,2,3-pentafluoro-1,3-dichloropropane, 2,3-dihydroperfluoropentane,1,1,1,2,2,4-hexafluorobutane,1-trifluoromethyl-1,2,2-trifluorocyclobutane,3-methyl-1,1,2,2-tetrafluorocyclobutane, 1-hydropentadecafluoroheptane,and mixtures thereof.

The above-described alkoxy-substituted perfluorocompounds can be usefulnot only in cleaning but also in coating deposition, where theperfluorocompound functions as a carrier for a coating material toenable deposition of the material on the surface of a substrate. Theinvention thus also provides a coating composition and a process fordepositing a coating on a substrate surface using the composition. Theprocess comprises the step of applying to at least a portion of at leastone surface of a substrate a coating of a liquid coating compositioncomprising (a) a solvent composition comprising at least one mono-, di-,or trialkoxy-substituted perfluoroalkane, perfluorocycloalkane,perfluorocycloalkyl-containing perfluoroalkane, orperfluorocycloalkylene-containing perfluoroalkane compound, the compoundoptionally containing additional catenary heteroatoms; and (b) at leastone coating material which is soluble or dispersible in the solventcomposition. The solvent composition can further comprise one or moreco-dispersants or co-solvents (as defined supra, preferably those havingboiling points below about 125° C.) and/or one or more additives (e.g.,surfactants, coloring agents, stabilizers, anti-oxidants, flameretardants, and the like). Preferably, the process further comprises thestep of removing the solvent composition from the coating by, e.g.,allowing evaporation (which can be aided by the application of, e.g.,heat or vacuum).

Coating materials which can be deposited by the process includepigments, lubricants, stabilizers, adhesives, anti-oxidants, dyes,polymers, pharmaceuticals, release agents, inorganic oxides, and thelike, and combinations thereof. Preferred materials includeperfluoropolyether, hydrocarbon, and silicone lubricants; amorphouscopolymers of tetrafluoroethylene; polytetrafluoroethylene; andcombinations thereof. Representative examples of materials suitable foruse in the process include titanium dioxide, iron oxides, magnesiumoxide, perfluoropolyethers, polysiloxanes, stearic acid, acrylicadhesives, polytetrafluoroethylene, amorphous copolymers oftetrafluoroethylene, and combinations thereof. Any of the substratesdescribed above (for cleaning applications) can be coated via theprocess of the invention. The process can be particularly useful forcoating magnetic hard disks or electrical connectors withperfluoropolyether lubricants or medical devices with siliconelubricants.

To form a coating composition, the components of the composition (i.e.,the alkoxy-substituted perfluorocompound(s), the coating material(s),and any co-dispersant(s) or co-solvent(s) utilized) can be combined byany conventional mixing technique used for dissolving, dispersing, oremulsifying coating materials, e.g., by mechanical agitation, ultrasonicagitation, manual agitation, and the like. The solvent composition andthe coating material(s) can be combined in any ratio depending upon thedesired thickness of the coating, but the coating material(s) preferablyconstitute from about 0.1 to about 10 weight percent of the coatingcomposition for most coating applications.

The deposition process of the invention can be carried out by applyingthe coating composition to a substrate by any conventional technique.For example, the composition can be brushed or sprayed (e.g., as anaerosol) onto the substrate, or the substrate can be spin-coated.Preferably, the substrate is coated by immersion in the composition.Immersion can be carried out at any suitable temperature and can bemaintained for any convenient length of time. If the substrate is atubing, such as a catheter, and it is desired to ensure that thecomposition coats the lumen wall, it may be advantageous to draw thecomposition into the lumen by the application of reduced pressure.

After a coating is applied to a substrate, the solvent composition canbe removed from the coating by evaporation. If desired, the rate ofevaporation can be accelerated by application of reduced pressure ormild heat. The coating can be of any convenient thickness, and, inpractice, the thickness will be determined by such factors as theviscosity of the coating material, the temperature at which the coatingis applied, and the rate of withdrawal (if immersion is utilized).

Objects and advantages of this invention are further illustrated by thefollowing examples, but the particular materials and amounts thereofrecited in these examples, as well as other conditions and details,should not be construed to unduly limit this invention.

EXAMPLES

The environmental impact of the alkoxy-substituted perfluorocompoundsused in the processes and compositions of the invention was assessed bydetermination of the atmospheric lifetime and the global warmingpotential (GWP) of certain compounds, as described below:

Atmospheric Lifetime

The atmospheric lifetime (t_(sample)) of various sample compounds wascalculated by the technique described in Y. Tang, Atmospheric Fate ofVarious Fluorocarbons, M.S. Thesis, Massachusetts Institute ofTechnology (1993). According to this technique, an ultraviolet (UV) gascell was charged with a sample compound, a reference compound (eitherCH₄ or CH₃Cl), ozone, and water vapor. Hydroxyl radicals were thengenerated by photolytic decomposition of the ozone in the presence ofthe water vapor and an inert buffer gas, i.e., helium. As the samplecompounds and reference compounds reacted with the hydroxyl radicals inthe gas phase, their concentrations were measured by Fourier transforminfrared spectroscopy (FTIR). The rate constant for reaction of thesample compound (k_(sample)) with hydroxyl radical was measured relativeto the rate constant for a reference compound (k_(ref)), and theatmospheric lifetime was then calculated using the following formula(where t_(CH4) and k_(CH4) are known values of 12 years and 6.5×10⁻¹⁵cm³/molecule-sec, respectively):$\tau_{sample} = \frac{\tau_{CH4}}{\left( \frac{k_{sample}}{k_{ref}} \right)\quad \left( \frac{k_{ref}}{k_{CH4}} \right)}$

The rate constant for each sample compound was measured (using CH₄ asthe reference compound and again using CH₃Cl) at 298K, and theatmospheric lifetime values were calculated and then averaged. Theresults are shown in Table A under the heading “Atmospheric Lifetime.”For comparative purposes, the atmospheric lifetime for severalhydrofluorocarbons is also shown in Table A.

Atmospheric lifetime was also estimated from a correlation developedbetween the highest occupied molecular orbital (HOMO) energy and theknown atmospheric lifetimes of hydrofluorocarbons and hydrofluorocarbonethers, in a manner similar to that described by Cooper et al. in Atmos.Environ. 26A, 7, 1331 (1992). The correlation differed from that foundin Cooper et al. in the following respects: the correlation wasdeveloped using a larger data set; lifetimes for the correlations weredetermined by relative hydroxyl reactivity of the sample to CH₃CCl₃ at277K, as described by Zhang et al. in J. Phys. Chem. 98(16), 4312(1994); HOMO energy was calculated using MOPAC/PM3, a semi-empiricalmolecular orbital package; and the number of hydrogen atoms present inthe sample was included in the correlation. The results are reported inTable A under the heading “Estimated Atmospheric Lifetime.”

Global Warming Potential

Global warming potential (GWP) was determined for the various samplecompounds using the above-described calculated values for atmosphericlifetime and experimentally determined infrared absorbance dataintegrated over the spectral region of interest, typically 500 to 2500cm⁻¹. The calculations were based on the definition of GWP set forth bythe Intergovernmental Panel in Climate Change in Climate Change: TheIPCC Scientific Assessment, Cambridge University Press (1990). Accordingto the Panel, GWP is the integrated potential warming due to the releaseof 1 kilogram of sample compound relative to the warming due to 1kilogram of CO₂ over a specified integration time horizon (ITH) usingthe following equation:${GWP}_{sample} = \frac{\int_{0}^{ITH}{\Delta \quad T_{x}C_{o_{x}}e^{{- t}/\tau_{x}}{t}}}{\int_{0}^{ITH}{\Delta \quad T_{{CO}_{2}}C_{{co}_{2}}{t}}}$

where ΔT is the calculated change in temperature at the earth's surfacedue to the presence of a particular compound in the atmosphere[calculated using a spreadsheet model (using parameters described byFisher et al. in Nature 344, 513 (1990)) derived from Atmospheric andEnvironmental Research, Inc.'s more complete one-dimensionalradiative-convective model (described by Wang et al. in J. Atmos. Sci.38, 1167 (1981) and J. Geophys. Res. 90, 12971 (1985)], C is the${GWP}_{sample} = \frac{\Delta \quad T_{x}C_{o_{x}}{\tau_{x}\left\lbrack {1 - e^{{- {ITH}}/\tau_{x}}} \right\rbrack}}{\begin{matrix}{\Delta \quad {{T_{{CO}_{2}}\left( {1.3 \times 10^{- 10}} \right)}\quad\left\lbrack {{A_{1}{\tau_{1}\left( {1 - e^{{- {ITH}}/\tau_{1}}} \right)}} +} \right.}} \\\left. {{A_{2}{\tau_{2}\left( {1 - e^{{- {ITH}}/\tau_{2}}} \right)}} + {A_{3}{\tau_{3}\left( {1 - e^{{- {ITH}}/\tau_{3}}} \right)}}} \right\rbrack\end{matrix}}$

atmospheric concentration of the compound, t is the atmospheric lifetimeof the compound (the calculated value described above), and x designatesthe compound of interest. Upon integration, the formula is as follows:where A₁=0.30036, A₂=0.34278, A₃=0.35686, τ₁=6.993, τ₂=71.108, andτ₃=815.73 in the Siegenthaler (1983) coupled ocean-atmosphere CO₂ model.The results of the calculations are shown in Table A below.

TABLE A Estimated Global Atmospheric Atmospheric Warming LifetimeLifetime Potential Compound (years) (years) (100 year ITH) CF₃—CH₃ 62.2CF₃—O—CH₃ 1.6 C₂F₅—CH₃ 12.6 C₂F₅—O—CH₃ 1.6 C₃F₇—CH₃ 9.6 C₃F₇—O—CH₃ 1.9C₄F₉—CH₃ 7.0 C₄F₉—O—CH₃ 1.9 5.5 330 C₄F₉—C₂H₅ 2.0 C₄F₉—O—C₂H₅ 0.5 1.2 70C₅F₁₁OCH₃ 4.3 CF₃CF(OCH₃)CF(CF₃)₂ 4—5 C₅F₁₁OC₂H₅ ˜1 c-C₆F₁₁—CH₃ 13.7c-C₆F₁₁—O—CH₃ 1.8 3.8 170 C₂F₅CF(OCH₃)CF(CF₃)₂ 4—5 CF₃CFHCFHCF₂CF₃ 23*1000 *A. M. Schmoltner et al., J. Phys. Chem 97,8976 (1993)

As can be seen in Table A, each of the various alkoxy-substitutedperfluorocompounds unexpectedly has a lower atmospheric lifetime thanthe corresponding hydrofluorocarbon, i.e., the hydrofluorocarbon havingthe same carbon number. The alkoxy-substituted perfluorocompounds arethus more environmentally acceptable than the hydrofluorocarbons (whichhave previously been proposed as chlorofluorocarbon replacements).

The chemical stability of the alkoxy-substituted perfluorocompounds usedin the processes and compositions of the invention was also evaluated todetermine their suitability for use in cleaning and coatingapplications. In these tests, a compound was contacted with a chemicalagent such as aqueous sodium acetate, aqueous KOH, concentrated sulfuricacid, or potassium permanganate in acetone to determine the stability ofthe compound to base, acid, or oxidant, as described below:

Stability in the Presence of Base

To assess hydrolytic stability, a ten gram sample of alkoxy-substitutedperfluorocompound was combined with 10 g of 0.1M NaOAc and sealed in a2.54 cm (internal diameter) by 9.84 cm Monel™ 400 alloy (66% nickel,31.5% copper, and 1.2% iron and several minor components) tube(available from Paar Instrument Co. of Moline, Ill. as Part Number 4713cm). The tube was heated at 110° C. in a forced air convection oven for16 hours. After cooling to room temperature, a 1 mL sample of the tubecontents was diluted with 1 mL of total ionic strength adjustment buffer(TISAB, available from Orion Research, Inc., a mixture of1,2-cyclohexylene dinitrilotetraacetic acid, deionized water, sodiumacetate, sodium chloride, and acetic acid). The concentration offluoride ion (resulting from any reaction of the perfluorocompound withthe aqueous NaOAc) was measured using an Orion Model 720A Coulombmeterwith a F specific electrode which had been previously calibrated using0.5 and 500 ppm F solutions. Based on the measured fluoride ionconcentration, the rate at which HF had been generated by reaction ofthe aqueous NaOAc with the perfluorocompound was calculated. The resultsare shown below in Table B and indicate that the alkoxy-substitutedperfluorocompounds are much more stable to base than is the comparativecompound.

TABLE B C₄F₉OCH₃ C₄F₉OC₂H₅ c-C₆F₁₁OCH₃ CF₃CFHCFHCF₂CF₃ HF Generation0.67 0.22 0.33 42.9 Rate (μg/g/hr)

To assess hydrolytic stability under more severely basic conditions,C₄F₉OCH₃ (125 g of 99.8% purity, 0.5 mole) was combined with potassiumhydroxide (29.4 g, 0.45 mole, dissolved in 26.1 g water) in a 250 mLflask equipped with an overhead stirrer, a condenser, and a thermometer,and the resulting solution was refluxed at 58° C. for 19 hours. Water(50 mL) was added to the solution after refluxing, and the resultingproduct was distilled. The lower fluorochemical phase of the resultingdistillate was separated from the upper phase and was washed with water(100 mL) to yield 121.3 g of recovered C₄F₉OCH₃, which was identical inpurity and composition to the starting material (as shown by gaschromatography). The aqueous base solution remaining in the reactionflask was titrated with standard 1.0 N HCl to reveal that none of theKOH originally charged had been consumed, indicating that theperfluorocompound was stable in the presence of the base.

Stability in the Presence of Acid

To assess hydrolytic stability under acidic conditions, C₄F₉OCH₃ (15 g,0.06 mole) was combined with sulfuric acid (10 g of 96% by weight, 0.097mole) in a 50 mL flask containing a stir bar and fitted with a refluxcondenser. The resulting mixture was stirred for 16 hours at roomtemperature, and then the resulting upper fluorochemical phase wasseparated from the resulting lower sulfuric acid phase. Gas-liquidchromatographic (GLC) analysis of the fluorochemical phase revealed thepresence of only the starting perfluorocompound and no detectable amountof C₃F₇CO₂CH₃, the expected product of hydrolysis. This result(indicating that the perfluorocompound was stable in the presence of theacid) was surprising in view of the discussion by England in J. Org.Chem. 49, 4007 (1984), which states that “[f]luorine atoms attached tocarbon which also bears an alkyl ether group are known to be labile toelectrophilic reagents. They are readily hydrolyzed in concentratedsulfuric acid, thus providing a route to some esters of fluoroacids.”

Stability in the Presence of Oxidant

To assess oxidative stability, potassium permanganate (20 g, 0.126 mole)was dissolved in acetone, and C₄F₉OCH₃ (500 g of 99.9% purity, 2.0 mole)was added to the resulting solution. The solution was refluxed for fourhours, with no indication that the permanganate had been consumed (asevidenced by the absence of brown MnO₂). The refluxed solution was thendistilled into a 500 mL Barrett trap filled with water. The lowerfluorochemical phase of the resulting mixture was separated from theupper phase, was washed with four 1.5 L aliquots of water, and was driedby passage through a column of silica gel to yield 471 g of resultingproduct. Gas chromatographic analysis of the product revealed noevidence of degradation of the starting perfluorocompound, indicatingthat the compound was stable in the presence of the oxidant.

Flash Point Testing

The alkoxy-substituted perfluorocompounds C₄F₉OCH₃, C₄F₉OC₂H₅, andc-C₆F₁₁OCH₃ were tested for flash point by the standard method definedby ASTM D3278-89. Each compound was determined to have no flash point.

Examples 1-7 Describe the Preparation of Novel Alkoxy-substitutedPerfluorocompounds of the Invention. Example 1 Preparation ofc-C₆F₁₁CF₂OC₂H₅

A one liter jacketed round bottom flask was equipped with a refluxcondenser, an overhead stirrer, and an addition funnel. The flask wascharged with anhydrous dimethyl formamide (300 g) and diethyl sulfate(239 g, 1.55 mole) under a flow of dry nitrogen gas. The resultingstirred solution was cooled to −20° C., and spray-dried potassiumfluoride (Aldrich Chemical, which was further dried at 120° C., 67.5 g,1.16 mole) was added. A mixture of perfluorocyclohexane carbonylfluoride and isomers of perfluoro methylcyclopentane carbonyl fluoride(approximately 80% purity, 318 g, 0.77 mole) was then added to theresulting mixture over a period of 45 minutes. (Hereinafter,c-C₆F₁₁—refers to a mixture of the perfluorinated cyclohexyl and methylcyclopentyl isomers.) The mixture was held at −20° C. for two hours andthen allowed to come to ambient temperature while stirring overnight.The mixture was transferred to a two liter round bottom flask and washeated to 50° C. for one hour. One liter of water was added and theresulting mixture distilled. The lower fluorochemical phase of theresulting distillate was then separated from the upper phase and waswashed once with water to afford 236 g of 61.9% purity c-C₆F₁₁CF₂OC₂H₅.The product was distilled to a purity of 99% (b.=128-134° C.). Theproduct identity was confirmed by gas chromatography/ mass spectrometry(GCMS) and by ¹H and ¹⁹F nuclear magnetic resonance spectroscopy (NMR).

Example 2 Preparation of c-C₆F₁₁CF₂OCH₃

A 500 mL round bottom flask was equipped with an overhead stirrer, acondenser, and an addition funnel, and was then charged with spray-driedpotassium fluoride (Aldrich, which was further dried at 120° C., 39.8 g,0.68 mole) and anhydrous dimethyl formamide (250 g). c-C₆F₁₁COF (150 gof 70% purity, 0.32 mole) was added slowly to the resulting mixture atroom temperature. An ice bath was then placed around the flask, anddimethyl sulfate (74.8 g, 0.59 mole) was added dropwise. The resultingmixture was held in the ice bath for five hours, followed by warming toambient temperature with stirring overnight. Water (100 mL) was thenadded to the mixture, and the resulting product was distilled. The lowerfluorochemical phase of the resulting distillate was separated from theupper aqueous phase to yield 143 g of c-C₆F₁₁CF₂OCH₃ of 63% purity. Theproducts of several reactions were combined and distilled (b.=110-120°C.). The product identity was confirmed by GCMS and by ¹H and ¹⁹F NMR.

Example 3 Preparation of 4-CF₃-c-C₆F₁₀CF₂OCH₃

A one liter round bottom flask was equipped with an overhead stirrer, acondenser, and an addition funnel and was then charged with spray-driedpotassium fluoride (Aldrich, which was further dried at 120° C., 15.4 g,0.26 mole), anhydrous cesium fluoride (6.5 g, 0.043 mole), and anhydrousdimethyl formamide (250 g). A mixture of perfluoro-4-methylcyclohexanecarbonyl fluoride and perfluorodimethyl cyclopentane carbonyl fluorides(100 g of 72% purity, 0.189 mole) was then added to the resultingmixture, and the mixture was stirred at ambient temperature for fourhours. Dimethyl sulfate (33.3 g, 0.264 mole) was then added to thestirred mixture, and the mixture was further stirred for 72 hoursfollowed by addition of water (500 mL).

The mixture was worked up essentially as described in Example 1 to yield67 g of a mixture of several components, which was subsequentlydistilled to give 26.5 g of 4-CF₃-c-C₆F₁₀CF₂OCH₃ (b.=118-137° C.) of 88%purity. product identity was confirmed by GCMS and by ¹H and ¹⁹F NMR,which showed the product to be about 60% of the trans-1,4 isomer and 15%of the cis-1,4 isomer. The product also contained several other isomersof CF₃-c-C₆F₁₀CF₂OCH₃, resulting from isomers of theperfluoromethylcyclohexane carbonyl fluoride which were present in thestarting material.

Example 4 Preparation of

The title compound was prepared essentially as in Example 3 usinganhydrous potassium fluoride (27 g, 0.46 mole), anhydrous dimethylformamide (250 g), perfluoro-3-piperidinopropionyl fluoride (322 g of40.4% purity, 0.32 mole), and dimethyl sulfate (52 g, 0.41 mole). 275 gof a product mixture of 38% purity was obtained, which was fractionallydistilled to give a main fraction of the desired compound (b.=137-139°C., 91% purity). The product identity was confirmed by infraredspectroscopy (IR), GCMS, and ¹H and ¹⁹F NMR.

Example 5 Preparation of

The title compound was prepared essentially as in Example 3 usinganhydrous potassium fluoride (42 g, 0.72 mole), anhydrous dimethylformamide (300 g), perfluoro-2-piperidinoacetyl fluoride (354 g of 47.2%purity, 0.46 mole), and diethyl sulfate (94 g, 0.61 mole). 349 g of aproduct mixture of 39% purity was obtained, which was fractionallydistilled to give a main fraction of the desired compound (b.=135-137°C.). The product identity was confirmed by IR, GCMS, and ¹H and ¹⁹F NMR.

Example 6 Preparation of

The title compound was prepared essentially as in Example 3 usinganhydrous potassium fluoride (17.7 g, 0.30 mole), anhydrous dimethylformamide (300 g), perfluoro-3-morpholinopropionyl fluoride (890 g of8.6% purity, 0.2 mole), and dimethyl sulfate (37 g, 0.29 mole). 88 g ofa product mixture of 57% purity was obtained, which was fractionallydistilled to give a main fraction of the desired compound (b.p.=129° C.,90% purity). The product identity was confirmed by IR, GCMS, and ¹H and¹⁹F NMR.

Example 7 Preparation of CH₃OCF₂-c-C₆F₁₀CF₂OCH₃

The title compound was prepared essentially as in Example 3 usinganhydrous potassium fluoride (6.62 g, 0.011 mole), anhydrous dimethylformamide (200 g), FCO-c-C₆F₁₀COF (253 g of approximately 26% purity,0.185 mole; the remainder of the material comprised a mixture ofmono-functional, non-functional, and isomeric compounds), and dimethylsulfate (14.4 g, 0.011 mole). 21 g of solid CH₃OCF₂-c-C₆F₁₀CF₂OCH₃ wasobtained (product identity confirmed by IR and ¹H and ¹⁹F NMR).

Examples 8-28 Describe the Use of Alkoxy-substituted Perfluorocompoundsin Various Different Cleaning Applications According to the CleaningProcess of the Invention

A number of different alkoxy-substituted perfluorocompounds wereprepared for use in cleaning, as described below:

Preparation of C₄F₉OC₂H₅

A 20 gallon Hastalloy C reactor, equipped with a stirrer and a coolingsystem, was charged with spray-dried potassium fluoride (7.0 kg, 120.3mole). The reactor was sealed, and the pressure inside the reactor wasreduced to less than 100 torr. Anhydrous dimethyl formamide (22.5 kg)was then added to the reactor, and the reactor was cooled to below 0° C.with constant agitation. Heptafluorobutyryl fluoride (22.5 kg of 58%purity, 60.6 mole) was added to the reactor contents. When thetemperature of the reactor reached −20° C., diethyl sulfate (18.6 kg,120.8 mole) was added to the reactor over a period of approximately twohours. The resulting mixture was then held for 16 hours with continuedagitation, was raised to 50° C. for an additional four hours tofacilitate complete reaction, and was cooled to 20° C. Then, volatilematerial (primarily perfluorooxacyclopentane present in the startingheptafluorobutyryl fluoride) was vented from the reactor over athree-hour period. The reactor was then resealed, and water (6.0 kg) wasadded slowly to the reactor. After the exothermic reaction of the waterwith unreacted perfluorobutyryl fluoride subsided, the reactor wascooled to 25° C., and the reactor contents were stirred for 30 minutes.The reactor pressure was carefully vented, and the lower organic phaseof the resulting product was removed to afford 17.3 kg of material whichwas 73% C₄F₉OC₂H₅ (b.p.=75° C.). The product identity was confirmed byGCMS and by ¹H and ¹⁹F NMR.

Preparation of C₄F₉OCH₃

The reaction was carried out in the same equipment and in a similarmanner to the procedure of Example 7 above, but using the followingmaterials: spray-dried potassium fluoride (6 kg, 103.1 mole), anhydrousdimethyl formamide (25.1 kg), perfluorobutyryl fluoride (58% purity,25.1 kg, 67.3 mole), and dimethyl sulfate (12.0 kg, 95.1 mole). 22.6 kgof product was obtained, which was 63.2% C₄F₉COH₃ (b.=58-60° C.). Theproduct identity was confirmed by GCMS and by ¹H and ¹⁹F NMR.

Preparation of c-C₆F₁₁OCH₃

A 500 ml, 3-necked round bottom flask equipped with an overhead stirrer,an addition funnel, and a condenser was charged with anhydrous cesiumfluoride (27.4 g, 0.18 mole), anhydrous diethylene glycol dimethyl ether(258 g, hereinafter diglyme), and dimethyl sulfate (22.7 g, 0.18 mole).Perfluorocyclohexanone (50g, 0.18 mole) was then added dropwise to theresulting stirred mixture, and stirring was continued for 18 hours afterthe addition. Water (approximately 200 ml) was added to the resultingmixture, and the lower fluorochemical phase of the mixture was separatedfrom the upper phase and washed once with saturated aqueous sodiumchloride solution. Since the fluorochemical phase still contained about12% diglyme, water was added to it, and the resulting product wasazeotropically distilled to yield 32.8 g of c-C₆F₁₁OCH₃ (b.p.=100° C.),which was free of diglyme. The product identity was confirmed by IR,GCMS, and ¹H and ¹⁹F NMR.

Preparation of (CF₃)₂CFCF₂OCH₃

The title compound was prepared essentially as in Example 1 usinganhydrous potassium fluoride (31.9 g, 0.55 mole), anhydrous dimethylformamide (186 g), perfluoroisobutryl fluoride (108 g of 99% purity, 0.5mole), and dimethyl sulfate (81.9 g, 0.65 mole). The resulting mixturewas held at −20° C. for 16 hours, was warmed to 40° C. for 3.5 hours,and was then distilled to yield 109 g of the title compound (83.6%purity by GLC; also containing 11.6% (CF₃)₂CFCOF). The reaction mixturesfrom several runs were combined and distilled (b.=60-61° C.).

Preparation of (CF₃)₂CFCF₂OC₂H₅

The title compound was prepared essentially as in Example 1 usinganhydrous potassium fluoride (31.9 g, 0.55 mole), anhydrous dimethylformamide (184 g), perfluoroisobutryl fluoride (112.3 g of 77% purity,0.4 mole), and diethyl sulfate (100.1 g, 0.65 mole). The resultingmixture was worked up essentially as in Example 3 to yield 80 g of thetitle compound. The product identity was confirmed by IR, GCMS, and ¹Hand ¹⁹F NMR.

Preparation of C₈F₁₇OCH₃

The title compound was prepared essentially as in Example 3 usinganhydrous potassium fluoride (6.62 g, 0.011 mole), anhydrous dimethylformamide (800 g), C₇F₁₅COF (456.7 g, 1.09 mole), and dimethyl sulfate(14.4 g, 0.011 mole). The resulting mixture was worked up essentially asin Example 3 to give 444 g of the title compound (99.7% purity,b.=142-144° C.). The product identity was confirmed by IR, GCMS, and ¹Hand ¹⁹F NMR.

Preparation of C₂F₅CF(OCH₃)CF(CF₃)₂

The title compound was prepared essentially as in Example 3 usinganhydrous potassium fluoride (7.2 g, 0.123 mol), anhydrous diethyleneglycol dimethyl ether (diglyme, 60 g), methyltrialkyl(C₈-C₁₀)ammoniumchloride (Adogen™ 464, available from Aldrich Chemical Company, 1.8 g;which can preferably be purified by addition of anhydrous diglyme,followed by vacuum distillation up to the boiling point of diglyme, toremove any low boiling components and some diglyme to give a finalconcentration of approximately 50% by weight of Adogen™ 464 in diglyme),C₂F₅COCF(CF₃)₂(30 g, 0.095 mol, prepared by the reaction ofpentafluoropropionyl fluoride with KF and hexafluoropropene), anddimethyl sulfate (15.5 g, 0.123 mol). The reaction mixture was stirredat room temperature for 72 hours. Approximately 100 mL of 10% aqueouspotassium hydroxide was then added to the reaction mixture, and theresulting product was azeotropically distilled from the mixture. Thelower phase of the resulting distillate was separated from the upperphase, was washed with water, and was distilled to give 26.7 g ofproduct ether (boiling range 90-92° C.;>99% purity by gas-liquidchromatography (GLC)). The product identity was confirmed by GCMS and ¹Hand ¹⁹F NMR.

Preparation of C₃F₇OCH₃

A jacketed one liter round bottom flask was equipped with an overheadstirrer, a solid carbon dioxide/acetone condenser, and an additionfunnel. The flask was charged with spray-dried potassium fluoride (85 g,1.46 mol) and anhydrous diethylene glycol dimethyl ether (375 g) and wasthen cooled to about −20° C. using a recirculating refrigeration system.C₂F₅COF (196 g, 1.18 mol) was added to the flask over a period of aboutone hour. The flask was then warmed to about 24° C., and dimethylsulfate (184.3 g, 1.46 mol) was then added dropwise via the additionfunnel over a 45 minute period. The resulting mixture was then stirredat room temperature overnight. Water (a total of 318 mL) was then addeddropwise to the mixture. The mixture was transferred to a one literround bottom flask, and the resulting product ether was azeotropicallydistilled. The lower product phase of the resulting distillate wasseparated from the upper aqueous phase, was washed once with cold water,and was subsequently distilled to give 180 g of product (b.p. 36°C.;>99.9% purity by GLC). The product identity was confirmed by GCMS andby ¹H and ¹⁹F NMR.

Preparation of CF₃CF(OCH₃)CF(CF₃)₂

The title compound was prepared essentially as in Example 3 usinganhydrous potassium fluoride (12.8 g, 0.22 mol), anhydrous diethyleneglycol dimethyl ether (diglyme, 106 g), methyltrialkyl(C₈-C₁₀ )ammoniumchloride (Adogen™ 464, available from Aldrich Chemical Company, 4 g),CF₃COCF(CF₃)₂ (53.2 g, 0.20 mol, prepared essentially by the procedureof Smith et al., J. Am. Chem. Soc., 84, 4285 (1962)), and dimethylsulfate (33.9 g, 0.72 mol). Aqueous potassium hydroxide was added to thereaction mixture (approximately 25 g of 50% solution), followed by water(200 mL). The resulting crude product was azeotropically distilled fromthe reaction mixture. The lower phase of the resulting distillate wasseparated from the upper phase, was washed with water, was dried overanhydrous sodium sulfate, and was distilled (b.p. 82-83° C.; yield of 45g). The product identity was confirmed by GCMS and by FTIR.

Preparation of C₅F₁₁OCH₃

The title compound was prepared essentially as in Example 3 usinganhydrous potassium fluoride (32 g, 0.55 mol), anhydrous diethyleneglycol dimethyl ether (diglyme, 375 g), methyltrialkyl(C₈-C₁₀)ammoniumchloride (Adogen™ 464, available from Aldrich Chemical Company, 12.5 g;which can preferably be purified by addition of anhydrous diglyme,followed by vacuum distillation up to the boiling point of diglyme, toremove any low boiling components and some diglyme to give a finalconcentration of approximately 50% by weight of Adogen™ 464 in diglyme),C₄F₉COF (218 g of 60.7% purity, 0.5 mol), and dimethyl sulfate (69.3 g,0.55 mol). The reaction mixture was stirred at room temperatureovernight. Approximately 100 mL of 10% aqueous potassium hydroxide wasthen added to the mixture, and the resulting product was azeotropicallydistilled from the mixture. The lower phase of the resulting distillatewas separated from the upper phase, was washed with water, was treatedwith aqueous potassium hydroxide solution (53 g of 50%), and was thenrefluxed for one hour. A second azeotropic distillation and waterwashing yielded crude product which was further purified by distillationthrough a ten-plate perforated column to provide the product ether(boiling range 82-84° C.; 96.2% purity by GLC). The product identity wasconfirmed by GCMS and by ¹H and ¹⁹F NMR.

Preparation of C₅F₁₁OC₂H₅

The title compound was prepared essentially as in Example 3 usinganhydrous potassium fluoride (38.6 g, 0.67 mol), anhydrous diethyleneglycol dimethyl ether (diglyme, 500 g), methyltrialkyl(C₈-C₁₀)ammoniumchloride (Adogen™ 464, available from Aldrich Chemical Company, 10.5 g),C₄F₉COF (260 g of 60.7% purity, 0.59 mol), and diethyl sulfate (102.4 g,0.67 mol). The reaction mixture was stirred at room temperatureovernight, and then the resulting product was azeotropically distilledfrom the reaction mixture. The lower product phase of the resultingdistillate was separated from the upper phase and was treated withapproximately 50 g of 50% aqueous potassium hydroxide, was refluxed forfour hours, and was stirred at room temperature overnight. A secondazeotropic distillation and water washing gave crude product which wasfurther purified by distillation through a ten-plate perforated columnto provide the product ether (boiling point 96° C.; 99.6% purity byGLC). The product identity was confirmed by GCMS and by ¹H and ¹⁹F NMR.

Solvency Properties

A number of potential solvents were tested for their ability to dissolvehydrocarbons of increasing molecular weight according to the proceduredescribed in U.S. Pat. No. 5,275,669 (Van Der Puy et al.), thedescription of which is incorporated herein by reference. The data shownin Table 1 were obtained by determining the largest normal hydrocarbonalkane which was soluble in a particular solvent at a level of 50percent by volume. The numbers in the Table correspond with the carbonnumber of the largest alkane, e.g., “8” refers to octane. Measurementswere made from room temperature up to the boiling point of the solvent.For comparative purposes, hydrofluorocarbons (HFCs) and perfluorocarbons(PFCs) were also tested using this method.

TABLE 1 Temperature (° C.) C₄F₉OCH₃ C₄F₉OC₂H₅ c-C₆F₁₁OCH₃ CF₃CFHCFHC₂F₅C₆F₁₄ C₈F₁₈ C₅F₁₁H C₆F₁₃H 23  9 12 10 7 6 5 7 7 30 10 12 11 7 40 10 1311 8 6 6 8 8 50 12 14 13 8 7 6 8 55 12 15 13 9 60 12 15 13 7 7 9 73 1715 7 10  101  18 9

The data in Table 1 show that hydrocarbon alkanes are significantly moresoluble in the alkoxy-substituted perfluorocompounds used in thecleaning process of this invention than in the comparative compounds,the HFCs and PFCs. This improved solvency was more pronounced atelevated temperatures. Thus, the cleaning process of the invention canbe used to remove higher molecular weight hydrocarbons (e.g., oils andgreases) from substrate surfaces than can be removed using HFCs or PFCs.The higher solvency of the alkoxy-substituted perfluorocompounds forhydrocarbon alkanes indicates that these perfluorocompounds can servenot only as superior cleaning solvents for removing hydrocarbon soils,but can also be effective as solvents for depositing hydrocarboncoatings, e.g., coatings of lubricant, onto substrate surfaces.

Using essentially the above-described method, the solvency properties ofother alkoxy-substituted perfluorocompounds were tested at roomtemperature. The compounds tested and the results obtained are shown inTable 2 below.

TABLE 2 Compound Largest Soluble

9

11 C₈F₁₇OCH₃ 6 (CF₃)₂CFCF₂OCH₃ 9

8

7

9

8

Examples 8-10 and Comparative Examples A-C

In the following Examples and Comparative Examples, the cleaning abilityof the alkoxy-substituted perfluorocompounds used in the cleaningprocess of the invention was further evaluated. A 1.28 cm×1.28 cm×0.225cm wire-wrapped, aluminum coupon was coated with white heavy mineral oil(available from Aldrich Chemical) by immersing the coupon in anoil-filled beaker. The initial amount of the oil on the coupon wasdetermined by weighing it on an analytical balance to the nearest 0.1mg. The coupon was immersed in a container of solvent and sonicated for1 minute at the indicated temperature (see Table 3 below for thesolvents and temperatures used). The coupon was then weighed again, andthe results were recorded in Table 3 as percent oil removal.

TABLE 3 Example 8 9 10 Comparative A Comparative B Comparative C Temp.(° C.) C₄F₉OCH₃ C₄F₉OC₂H₅ c-C₆F₁₁OCH₃ C₆F₁₄ C₆F₁₃H CF₂ClCFCl₂ 23 60.356.0 74.4 54.9 71.7 98.9 50 98.7 99.2 96.5 67.6 86.8 98.7 60 99.9 100.099.8

The data in Table 3 show that the alkoxy-substituted perfluorocompoundsremoved amounts of the mineral oil which were comparable to the amountsremoved by the comparative PFC and HFC compounds at room temperature. Atelevated temperature, the cleaning properties of the perfluorocompoundswere superior to those of the PFC and HFC compounds and equivalent tothose of the comparative CFC compound.

Examples 11-13

Using essentially the same procedure as that described in Examples 8-10,the ability of the alkoxy-substituted perfluorocompounds to remove afluorinated oil was evaluated. As in the previous Examples, a coupon wasimmersed in Krytox™ 157FSM perfluoropolyether oil having carboxylic acidend groups (available from DuPont), and the percent oil remaining afterimmersion in the solvent (at room temperature) was determined. Theresults are shown in Table 4 below.

TABLE 4 Example 11 12 13 Compound C₄F₉OCH₃ C₄F₉OC₂H₅ c-C₆F₁₁OCH₃ %Removed 99.1 99.3 96.5

The data show that the alkoxy-substituted perfluorocompounds veryeffectively removed the perfluoropolyether oil from the surface of thecoupon. This indicates that the perfluorocompounds can function well ascleaning solvents for the removal of halogenated compounds such ashalogenated oils and greases.

Examples 14-16 and Comparative Examples D-E

The ability of alkoxy-substituted perfluorocompounds to function as arinse agent in a co-solvent cleaning process was evaluated. Theabove-described aluminum coupon was coated with solder flux (availablefrom Alpha Metals as Alpha 611 rosin, mildly activated flux) byimmersing the coupon into a flux-filled beaker. The flux-coated couponwas then dried using a forced air convection drier. The initial amountof the flux on the coupon was determined by weighing it on an analyticalbalance to the nearest 0.1 mg. The coupon was immersed in a container ofa mixed solvating agent comprising approximately 50% methyl decanoateand 50% dipropylene glycol di-n-butyl ether and was sonicated for 1minute at approximately 55° C. The coupon was then immersed for 30seconds into alkoxy-substituted perfluorocompound which had been heatedto its boiling point. The coupon was weighed again, and the results wererecorded in Table 5 below as percent oil removed from the coupon.

TABLE 5 Com- Com- para- para- Exam- tive tive ple 14 15 16 D E Com-C₄F₉OCH₃ C₄F₉OC₂H₅ c-C₆F₁₁OCH₃ C₆F₁₄ C₆F₁₃H pound % Re- 100.0 100.0100.0 51.9 91.2 moved

The data in Table 5 show that the alkoxy-substituted perfluorocompounds(used according to the cleaning process of the invention) effectivelyremoved the solvating agent and flux residues, showing solvencyproperties superior to those of the comparative PFC and HFC compounds.

Examples 17-18 and Comparative Example F

The above-described aluminum coupon was dipped into Brayco 815Zperfluoropolyether oil (available from Castrol Inc., molecular weight ofabout 10,000) and then immersed in alkoxy-substituted perfluorocompoundvapor (over the boiling liquid) for 60 seconds. The percent oil removalwas determined in the above-described manner. The results are shown inTable 6.

TABLE 6 17 18 Comparative F Compound C₄F₉OCH₃ C₄F₉OC₂H₅ C₆F₁₄ PercentSoil 89.9% 93.3% 92.9% Removed

Examples 19-20 and Comparative Example G

The above-described test coupon was dipped into a paraffinic oilcomprising a mixture of linear and branched hydrocarbons (DuoSeal PumpOil, available from Sargent Welch), was immersed in mixed solvatingagent comprising approximately 50% methyl caproate and 50% dipropyleneglycol di-n-butyl ether for 30 seconds, and was then rinsed in boilingalkoxy-substituted perfluorocompound for 30 seconds. The percent oilremoval was determined in the above-described manner. The results areshown in Table 7.

TABLE 7 19 20 Comparative G Compound C₄F₉OCH₃ C₄F₉OC₂H₅ C₆F₁₄ PercentSoil 99.8% 100.0% 89.2% Removed

Examples 21-22

The above-described test coupon was dipped in white heavy mineral oil(available from Aldrich Chemical), was immersed in a boilingsingle-phase mixture of 40 volume % of a solvating agent comprisingessentially methyl decanoate and 60 volume % of alkoxy-substitutedperfluorocompound (a cleaning composition of the invention) for 60seconds, was cooled for 60 seconds, and was then immersed in mixturevapor for 30 seconds. The percent oil removal was determined in theabove-described manner. The results are shown in Table 8.

TABLE 8 21 22 Fluorinated Component of C₄F₉OCH₃ C₄F₉OC₂H₅ CleaningComposition Percent Soil Removed 94.61% 94.28%

Examples 23-24 and Comparative Example H

The above-described test coupon was dipped into DuoSeal Pump Oil(available from Sargent-Welch), was immersed in a boiling mixture of 40volume % of a solvating agent comprising mixed terpenes having a boilingrange of 243-274° C. and 60 volume % of alkoxy-substitutedperfluorocompound (a cleaning composition of the invention), was cooledfor 60 seconds, and was then immersed in mixture vapor for 30 seconds.The percent oil removal was determined in the above-described manner.The results are shown in Table 9.

TABLE 9 23 24 Comparative H Fluorinated C₄F₉OCH₃ C₄F₉OC₂H₅ C₆F₁₄Component of Cleaning Composition Percent Soil Removed 86.4% 99.4% 75.7%

Examples 25-26 and Comparative Example I

The above-described test coupon was dipped into DuoSeal Pump Oil(available from Sargent-Welch) and was then immersed in a mixture of 40volume % n-C₆H₁₄ and 60 volume % alkoxy-substituted perfluorocompound (acleaning composition of the invention) for 60 seconds at roomtemperature with ultrasonic agitation. The percent oil removal wasdetermined in the above-described manner. The results are shown in Table10.

TABLE 10 25 26 Comparative I Fluorinated C₄F₉OCH₃ C₄F₉OC₂H₅ C₆F₁₄Component of Cleaning Composition Percent Soil 92.5% 99.0% 88.5% Removed

Examples 27-28 and Comparative Example J

The above-described test coupon was dipped into DuoSeal Pump Oil(available from Sargent-Welch) and was then immersed in the vapor of aboiling mixture of 40 volume % n-C₆H₁₄ and 60 volume %alkoxy-substituted perfluorocompound (a cleaning composition of theinvention) for 60 seconds. The percent oil removal was determined in theabove-described manner. The results are shown in Table 11.

TABLE 11 Example 27 28 Comparative J Fluorinated Component of C₄F₉OCH₃C₄F₉OC₂H₅ C₆F₁₄ Cleaning Composition Percent Soil Removed 90.8% 97.1%73.8%

The results obtained in Examples 17-28 show that alkoxy-substitutedperfluorocompounds are effective at removing a variety of contaminantsfrom substrate surfaces.

Examples 29-38 describe the preparation of coating compositions of theinvention and the evaluation of alkoxy-substituted perfluorocompoundsfor use according to the coating process of the invention.

Examples 29-31

The ability of alkoxy-substituted perfluorocompounds to dissolve severalhalogenated oils was determined by adding a measured amount of oil toalkoxy-substituted perfluorocompound until the resulting mixture becameturbid or phase-split. Miscibility was defined as greater than or equalto 50 percent by volume solubility at room temperature. The results(shown in Table 12) indicate that alkoxy-substituted perfluorocompoundshave very high ability to dissolve halogenated oils. Thus, theperfluorocompounds can be used as carrier solvents for halogenated oilsin the deposition of coatings of such oils on substrate surfaces.

TABLE 12 Example 29 30 31 Compound C₄F₉OCH₃ C₄F₉OC₂H₅ c-C₆F₁₁OCH₃ SoluteBrayco 815Z Miscible Miscible Miscible Perfluoropolyether (MW about10,000) Fomblin ™ AM-2001 Miscible Miscible Miscible FunctionalizedPerfluoropolyether (available from Ausimont Inc.)Chlorotrifluoroethylene Miscible Miscible Miscible Fluid (available fromInland as Inland 41 Vacuum Pump Oil)

Examples 32-38 and Comparative Examples K-L

To demonstrate the use of alkoxy-substituted perfluorocompounds asdispersing agents, a series of polytetrafluoroethylene (PTFE)dispersions were prepared and evaluated. Commercially, PTFE is availablefrom DuPont as Teflon™ powder or as Vydax™ dispersions in either wateror isopropanol (IPA)(20-30 weight %). To prepare useful coatings, theseconcentrated dispersions must be further diluted with a co-dispersant to1-10 weight %, more frequently 1-3 weight %. Although the commercialPTFE dispersions may be further diluted with either water orisopropanol, these fluids are often not preferred due to performanceand/or safety reasons.

In the following Examples 32-38, the commercially-available,concentrated dispersions were diluted at room temperature withalkoxy-substituted perfluorocompound or with a comparative compound(perfluoro-N-methyl morpholine) to produce a dilute dispersion ofapproximately 1.5 weight %. The resulting dispersions were thenevaluated as to homogeneity and assigned one of the ratings shown inTable 13 below. A description of the dispersions prepared and theresults obtained are shown in Table 14.

TABLE 13 Rating Rating Description Poor Agglomerated PTFE-not useful.Fair Some agglomeration; extensive grainy or waxy coating on the surfaceof glass vial. Good Homogeneous dispersion; some grainy coating on glassvial. Very Homogeneous dispersion; little to no grainy coating on glassGood vial.

TABLE 14 Final Dispersion Example No. Product Dispersant Weight % Rating32 Vydax ™ C₄F₉0CH₃ 1.49 Very Good AR/IPA 33 Vydax ™ C₄F₉0CH₃ 1.52 VeryGood HD/IPA 34 Teflon ™ C₄F₉0CH₃ 1.59 Very Good MP1100/IP A 35 Teflon ™C₄F₉0CH₂CH₃ 1.52 Very Good MP1100/IP A 36 Vydax ™ C₄F₉0CH₃ 0.92 Fair toGood ARW/Wate r 37 Vydax ™ C₄F₉0CH₂CH₃ 0.91 Fair to Good ARW/Wate r 38Vydax ™ C₄F₉0CH₂CH₃ 1.49 Fair to Good ARW/Wate r Comparative Vydax ™Perfluoro-N- 1.50 Poor K ARI/PA methyl morpholine Comparative Vydax ™Perfluoro-N- 1.50 Poor L ARW/Wate methyl r morpholine

The data show that alkoxy-substituted perfluorocompounds can be used toprepare homogeneous dispersions of PTFE, whereas the comparative PFCcompound cannot. Thus, the perfluorocompounds can be used as carriersolvents for PTFE in the deposition of coatings of PTFE on substratesurfaces.

Examples 39-44 describe the use of alkoxy-substituted perfluorocompoundsin water removal (drying) according to the cleaning process of theinvention.

Examples 39-44

A series of water displacement compositions was prepared and evaluated.The compositions comprised alkoxy-substituted perfluorocompound andeither a surface active agent (C₄F₉OC₂F₄OCF₂CONHC₂H₄OH, described inU.S. Pat. Nos. 5,125,978 and 5,089,152 (Flynn et al.)) or a co-solvent.The compositions (and the results obtained) are shown in Table 15 below.

The following procedure was utilized: an 11.7 mm O.D. by 32 mm glassvial was wetted with deionized water. The wetted vial was placed in avessel containing a water displacement composition which had been heatedto its boiling point. A saturated zone of alkoxy-substitutedperfluorocompound (and cosolvent, if any) vapor was maintained above theboiling composition. The vial was agitated by ultrasound for 1 minutewhile dislodging and displacing any adhering water. The vial was thenremoved from the boiling composition and held in the saturated vaporzone for 30-60 seconds to allow drainage of excess water displacementcomposition back into the vessel and thereby minimize fluid carryout.The vial was then visually inspected for the presence of residual water.The results are shown in Table 15 below, where a “+” indicates that 75%of the water was removed from the vial in 60 seconds.

TABLE 15 Concentration of Surface Active Ex. Alkoxy-substitutedCo-solvent (5 Agent Water No. Perfluorocompound Volume %) (weight %)Removal 39 C₄F₉OCH₃ None 0.2 + 40 C₄F₉OC₂H₅ None 0.2 + 41 C₄F₉OCH₃ CH₃OHNone + 42 C₄F₉OCH₃ (CH₃)₂CHOH None + 43 C₄F₉OC₂H₅ CH₃OH None + 44C₄F₉OC₂H₅ (CH₃)₂CHOH None +

The results in Table 15 show that alkoxy-substituted perfluorocompoundsare effective in removing water from substrate surfaces.

In Examples 45-65 and Comparative Examples M-Z and A′-G′, the propertiesof an alkoxy-substituted perfluorocompound used in the process andcomposition of this invention, perfluorobutyl methyl ether (C₄F₉OCH₃),were compared with the properties of 2-chloro-1,1,2-trifluoroethylmethyl ether (CHClFCF₂OCH₃), described in U.S. Pat. No. 3,278,615(Larsen et al.). Comparisons were made for both the neat ether compoundsand blends thereof with co-solvent.

Examples 45-65 and Comparative Examples M-Z and A′-G′

Various properties were measured for C₄F₉OCH₃, CHClFCF₂OCH₃, and blendsof each ether compound with co-solvent, trans-1,2-dichloroethylene(hereinafter, t-DCE) or n-butyl bromide, at various weight ratios. Theresults of these measurements are shown in Tables 16 and 17 below.

TABLE 16 Test Data for Test Data for Weight Weight C₄F₉OCH₃ CHClFCF₂OCH₃Comparative Test % Ether % t-DCE Ex. No. (Example) (Comp. Ex.) Ex. No.Open Cup 100   0 45 none 76 (24) M Flash Point (ASTM 80 20 46 none 85(29) N D1310-86), 50 50 47 none 80 (27) O ° F. (° C.) 20 80 48 none 80(27) P Largest Carbon Number 100   0 49  9 18 Q of Longest Hydrocarbon80 20 50 11 19 R Al-kane to Dissolve¹ 50 50 51 16 21 S 20 80 52 22 27 T¹Determined as described above in “Solvency Properties” section.

TABLE 17 Weight Test Data for Test Data for Weight % n-Butyl C₄F₉OCH₃CHClFCF₂OCH₃ Comparative Test % Ether Bromide Ex. No. (Example) (Comp.Ex.) Ex. No. Closed Cup 100   0 53 none⁴ 45 (7) U Flash Point 80 20 54none⁴ 50 (10) V (ASTM D3278-96), 50 50 55 none⁴ 45 (7) W ° F. (° C.) 3070 56 none⁴ 45 (10) X 20 80 57 none⁴ 50 (7) Y Atmospheric Life- 100   058 4.1 0.27 Z time (years)¹ Ozone Depletion 100   0 59 none⁵ 0.0015⁶ A′Potential (ODP) (CFC-11 = 1) Largest Carbon 100   0 60  9 18 B′ Numberof Longest 80 20 61 11 19 C′ Hydrocarbon Al- 50 50 62 15 20 D′ kane toDissolve² 30 70 63 21 21 E′ 20 80 64 21 21 F′ Stability in 100   0 65 norxn. (0% quantitative (100% G′ Presence of Acid³ conversion conversionto ester) to ester)

¹Determined as described above in “Atmospheric Lifetime” section, exceptbased upon an updated value of 8.9 years for the atmospheric lifetime ofmethane, as reported by R. G. Prinn et al. in Science, Volume 269, Jul.14, 1995, pages 187-192.

²Determined as described above in “Solvency Properties” section.

³Determined as described above in “Stability in the Presence of Acid”section.

⁴During testing, the temperature of the closed cup flash point apparatuswas gradually raised to 140° F. (60° C.). This upper temperature wasclose to the boiling point for the C₄F₉OCH₃ mixtures.

⁵Compounds containing fluorine as the only halogen have been shown tohave no impact on stratospheric ozone, as described by A. R.Ravishankara et al. in Science, Volume 263, Jan. 7, 1994, pages 71-75and by J. S. Francisco and M. M. Maricq in Accounts in Chemical Research29, 391-397 (1996).

⁶The estimated value for CHClFCF₂OCH₃ was based on HCFC 123, which hasan ODP of 0.012.

The data in Tables 16 and 17 shows that the alkoxy-substitutedperfluorocompound and blends thereof used in the process and compositionof this invention exhibit significantly different properties from thoseof the ether compound of U.S. Pat. No. 3,278,615 (hereinafter, the '615compound) and corresponding blends. For example, unlike the '615compound, the alkoxy-substituted perfluorocompound does not depletestratospheric ozone and is not flammable. The alkoxy-substitutedperfluorocompound exhibits superior chemical stability to that of the'615 compound (that is, the perfluorocompound does not hydrolyze in thepresence of acids, whereas the '615 compound is quantitatively convertedto ester). Finally, and most surprisingly, unlike the '615 compound, thealkoxy-substituted perfluorocompound does not form flammable mixtures orblends (over a wide range of weight ratios) with flammable co-solventssuch as trans-1,2-dichloroethylene and n-butyl bromide. Such blends ofperfluorocompound and flammable co-solvent can thus surprisingly be usedfor cleaning where desired.

Various modifications and alterations of this invention will becomeapparent to those skilled in the art without departing from the scopeand spirit of this invention.

What is claimed is:
 1. A coating composition comprising: (a) a solventcomposition comprising at least one mono-, di-, or trialkoxy-substitutedperfluoroalkane, perfluorocycloalkane, perfluorocycloalkyl-containingperfluoroalkane, or perfluorocycloalkylene-containing perfluoroalkanecompound, said compound optionally containing one or more additionalcatenated heteroatoms; and (b) at least one coating material that issoluble or dispersible in said solvent composition.
 2. The coatingcomposition according to claim 1, wherein said solvent compositionfurther comprises at least one co-solvent and/or at least one additive.3. The coating composition according to claim 2, wherein said co-solventis selected from the group consisting of alcohols, ethers, alkanes,alkenes, perfluorocarbons, perfluorinated tertiary amines,perfluoroethers, cycloalkanes, esters, ketones, aromatics, siloxanes,hydrochlorocarbons, hydrochlorofluorocarbons, and hydrofluorocarbons,and said additive is a surfactant.
 4. The coating composition accordingto claim 1, wherein said compound has a boiling point in the range offrom about 25° C. to about 200° C.
 5. The coating composition accordingto claim 1, wherein said compound is represented by the general formulaR_(f)—(O—R_(h))_(x), wherein x is an integer of 1 to 3; when x is 1,R_(f) is selected from the group consisting of linear or branchedperfluoroalkyl groups having from 2 to about 15 carbon atoms,perfluorocycloalkyl-containing perfluoroalkyl groups having from 5 toabout 15 carbon atoms, and perfluorocycloalkyl groups having from 3 toabout 12 carbon atoms; when x is 2, R_(f) is selected from the groupconsisting of linear or branched perfluoroalkanediyl groups orperfluoroalkylidene groups having from 2 to about 15 carbon atoms,perfluorocycloalkyl- or perfluorocycloalkylene-containingperfluoroalkanediyl or perfluoroalkylidene groups having from 6 to about15 carbon atoms, and perfluorocycloalkanediyl groups orperfluorocycloalkylidene groups having from 3 to about 12 carbon atoms;when x is 3, R_(f) is selected from the group consisting of linear orbranched perfluoroalkanetriyl groups having from 2 to about 15 carbonatoms, perfluorocycloalkyl- or perfluorocycloalkylene-containingperfluoroalkanetriyl groups having from 6 to about 15 carbon atoms, andperfluorocycloalkanetriyl groups having from 3 to about 12 carbon atoms;each R_(h) is independently selected from the group consisting of linearor branched alkyl groups having from 1 to about 8 carbon atoms,cycloalkyl-containing alkyl groups having from 4 to about 8 carbonatoms, and cycloalkyl groups having from 3 to about 8 carbon atoms;wherein either or both of the groups R_(f) and R_(h) can contain one ormore catenated heteroatoms; and wherein the sum of the number of carbonatoms in R_(f) and the number of carbon atoms in R_(h) is greater thanor equal to
 4. 6. The composition according to claim 1, wherein saidcoating material is selected from the group consisting of pigments,lubricants, stabilizers, adhesives, anti-oxidants, dyes, polymers,pharmaceuticals, release agents, inorganic oxides, and combinationsthereof.
 7. The composition according to claim 1, wherein said coatingmaterial is selected from the group consisting of perfluoropolyether,hydrocarbon, and silicone lubricants; copolymers of tetrafluoroethylene;polytetrafluoroethylene; and combinations thereof.
 8. A coatingcomposition comprising: (a) a solvent composition comprising at leastone compound selected from the group consisting of c-C₆F₁₁CF₂OC₂H₅,c-C₆F₁₁CF₂OCH₃, 4-CF₃-c-C₆F₁₀CF₂OCH₃,

(b) at least one coating material that is soluble or dispersible in saidsolvent composition.